USE OF ETHEPHON TO PROMOTE COLOR AND RIPENING 

 OF APPLES IN MASSACHUSETTS 



W.J. Lord and D.W. Greene 

 Department of Plant and Soil Sciences 



Ethephon is proving to be of significant value to both pro- 

 ducers and consumers of apples because a pre-harvest application 

 of this material will stimulate red color development, increase 

 soluble solids (sugar content) and hasten fruit maturity. These 

 responses make it possible to advance the marketing season of ap- 

 ples and to have high quality fruits for these early sales. Fur- 

 thermore, this chemical enables the grower to harvest a larger per- 

 centage of his crop from the trees at the first picking. Neverthe- 

 less, misuse of ethephon and/or unavoidable delay in harvest fol- 

 lowing its use could intensify our current problems of supply man- 

 agement and poor fruit condition with the 'Mcintosh' variety. The 

 placement in marketing channels of an excessive volume of ethephon- 

 treated 'Mcintosh' apples that must be sold quickly because of over- 

 maturity could depress prices. Ethephon must be used with caution! 



Successful Use of Ethephon 



Ethephon will not completely overcome conditions unfavorable 

 for development of red color. Our experience, the past 3 years, 

 has been that ethephon at 1/2 pint added 10 to 281 red color to 

 'Mcintosh' apples borne on the periphery of the trees within 7 or 

 8 days after application (Table 1). Two years' data have shown that 

 1/4 pint and 1/2 pint promoted comparable color increases within 

 7 or 8 days after application but the 1/2 pint rate softened fruit 

 (Table 1). 



Table 1. Influence of ethephon on red color development and flesh 

 firmness of 'Mcintosh' apples. Fruit harvest from peri- 



phery of the tree. 



Ethephon Flesh 



rate '^ Year ^ Red color firmness (lbs) 



9/13 (7 days after application) 

 1/2 pint 1972 71 15.2 



1/4 pint 1972 66 16.4 



Alar*, 1-1/2 lb 1972 54 16.7 



9/19 (8 days after application) 



1/2 pint 1973 78 15.2 



1/4 pint 1973 77 15.6 



Alar*, 1 lb 1973 68 15.7 



9/17 (7 days after application) 

 1/2 pint 1974 89 15.7 



Alar*, 1 lb 1974 61 16.9 



^All ethephon treatments were preceded by a mid-July application 

 of Alar*. In 1972, Alar* was used at 1-1/2 lb/100 gal; in 1973 

 and 1974 at 1 lb/100 gal. 

 ypenoprop (2,4,5-TP) applied with ethephon to control drop. Appli- 

 cation rate was 20 ppm in 1972 and 10 ppm in 1973 and 1974. 

 *Trade name 



